asp.net-mvc - 如何将模型传递给具有其他参数的 Action

Question

我的问题是，当我在DeleteEmployee中执行catch部分时，如何将ModelStateErrors发送到操作Employee

   public ActionResult Employee(int ID, string Name)
    {
        EmployeeListModel model = new EmployeeListModel (ID, projectName);
        return View(model);
    }

 public ActionResult DeleteEmployee(Employee emp)
    {

        try
        {
            emp.Delete();
            return RedirectToAction("Employee", new { ID = emp.ID, Name = emp.Name });
        }

        catch (Exception e)
        {
            EmployeeListModel model = new EmployeeListModel (emp.ID, emp.Name);
            ModelState.AddModelError("Error", e.Message);
            return RedirectToAction("Employee", model);
        }
    }

<小时/>

带 return View("Employee", model);我仍然无法将 ID 和名称作为参数发送。

Answer 1

使用 TempData 在多个 Controller 操作中持久保存 ModelState。

MvcContrib 有一个操作过滤器可以执行此操作。 Jeremy Skinner 编写了代码并在 http://www.jeremyskinner.co.uk/2008/10/18/storing-modelstate-in-tempdata-with-aspnet-mvc/ 上发表了一篇关于它的博客文章。 。那里的源链接已损坏，因此我发布了下面的代码。

ModelStateToTempDataAttribute Source Code

/// <summary>
/// When a RedirectToRouteResult is returned from an action, anything in the ViewData.ModelState dictionary will be copied into TempData.
/// When a ViewResultBase is returned from an action, any ModelState entries that were previously copied to TempData will be copied back to the ModelState dictionary.
/// </summary>
public class ModelStateToTempDataAttribute : ActionFilterAttribute
{
    public const string TempDataKey = "__MvcContrib_ValidationFailures__";

    /// <summary>
    /// When a RedirectToRouteResult is returned from an action, anything in the ViewData.ModelState dictionary will be copied into TempData.
    /// When a ViewResultBase is returned from an action, any ModelState entries that were previously copied to TempData will be copied back to the ModelState dictionary.
    /// </summary>
    /// <param name="filterContext"></param>
    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        var modelState = filterContext.Controller.ViewData.ModelState;

        var controller = filterContext.Controller;

        if(filterContext.Result is ViewResultBase)
        {
            //If there are failures in tempdata, copy them to the modelstate
            CopyTempDataToModelState(controller.ViewData.ModelState, controller.TempData);
            return;
        }

        //If we're redirecting and there are errors, put them in tempdata instead (so they can later be copied back to modelstate)
        if((filterContext.Result is RedirectToRouteResult || filterContext.Result is RedirectResult) && !modelState.IsValid)
        {
            CopyModelStateToTempData(controller.ViewData.ModelState, controller.TempData);
        }
    }

    private void CopyTempDataToModelState(ModelStateDictionary modelState, TempDataDictionary tempData)
    {
        if(!tempData.ContainsKey(TempDataKey)) return;

        var fromTempData = tempData[TempDataKey] as ModelStateDictionary;
        if(fromTempData == null) return;

        foreach(var pair in fromTempData)
        {
            if (modelState.ContainsKey(pair.Key))
            {
                modelState[pair.Key].Value = pair.Value.Value;

                foreach(var error in pair.Value.Errors)
                {
                    modelState[pair.Key].Errors.Add(error);
                }
            }
            else
            {
                modelState.Add(pair.Key, pair.Value);
            }
        }
    }

    private static void CopyModelStateToTempData(ModelStateDictionary modelState, TempDataDictionary tempData)
    {
        tempData[TempDataKey] = modelState;
    }
}

这里有一些类似的帖子

• ASP.NET MVC - How to Preserve ModelState Errors Across RedirectToAction?
• How can I maintain ModelState with RedirectToAction?